Neil deGrasse Tyson calculates how much Thor's hammer weighs

Legend says you can hold Thor's hammer if you're "worthy," but according to celebrity astrophysicist and all-around mastergeek Neil deGrasse Tyson, you'd also have to be really, really strong.

Tyson's Twitter account is an always-entertaining blend of science facts and nerdy musings. When he's not talking about the future of space exploration, he's thinking about how violent a zombie football game would be. Earlier this week, he took to thinking about Thor's hammer, and based on his knowledge of the building materials that went into the legendary weapon, he came up with an explanation for why it's so hard to lift.

If Thor's hammer is made of neutron-star matter, implied by legend, then it weighs as much as a herd of 300-billion elephants

If you're wondering, the average weight of a male African bush elephant is a bit more than 12,000 pounds. Females and younger specimens would weigh less, of course, and some impressive males could weigh even more, but even as a rough estimate, imagining trying to lift 300 billion of those is the kind of thing that could make Hulk wet himself.

So, unless you're very worthy, it's probably best to stay away from Mjolnir, lest Thor drop it on your toes. As for Tyson, he proved he's worthy of the hammer with a follow-up tweet.